Signals can be transmitted over various media (e.g., a wireless medium or a wired medium) between a transmitter and a receiver. Delay circuits for delaying signals can be added to a communication system for various purposes.
For example, adaptive communication systems can employ delay circuits. Examples of adaptive communication systems include a signal equalizer (used to compensate for distortion of a signal), a signal canceller (used to cancel one signal from another signal), an adaptive transversal signal filter (used to filter signals with variable filter coefficients), a self-interference canceller (used to cancel interference caused by transmitting and receiving signals at a same frequency or frequency band, such as for a full-duplex wireless transceiver), or other systems.
The amount of delay to use in a communication system can vary depending upon the particular condition or application. It can be challenging to provide delay circuits that can be controlled to achieve a desired wide tunable range of delays, while providing the ability to adjust signal delays incrementally at a desired delay resolution and while achieving linearity and uniform insertion loss across different delays.